Yoon Doo Joon
- Birth name: Yoon Doo Joon (Hangul: 윤두준)
- Date of birth: July 4, 1989 (1989-07-04)
- Position: Leader, Vocalist, Rapper, Dancer
Doo Joon was featured in AJ's music video for "Nunmureul Dakko" ("Wipe the Tears") as a rapper along with Jun Hyung before they debuted as part of BEAST. He was also a rapper for Gavy NJ's song "Sun Flower".
Doo Joon worked with Shin Sekyung on an ad for premium jeans brand, Buckaroo
When Girls' Generation member Taeyeon left MBC Radio FM4U 91.9Mhz ‘Chin Chin Radio’ , he was chosen as the temporary DJ for two weeks together with solo singer IU. Doo Joon was featured for G.Na's album title song ‘I’ll Back Off So You Can Live Better’ music video along with the other Beast member, Jun Hyung. Doojoon, Gi Kwang and IU appeared as special hosts on Music Core on August 21, 2010. DooJoon was cast in MBC daily sitcoms ‘All My Love.’ and 'More Charming By The Day'. On December 29, 2010, DooJoon was awarded with Rookie Comedy Award from the 2010 MBC Entertainment Awards for the cast in 'All My Love' and 'More Charming By The Day'.
Jang Hyun Seung
- Birth name: Jang Hyun Seung (Hangul: 장현승)
- Date of birth: September 3, 1989 (1989-09-03)
- Position: Vocalist, Lead Dancer
Yong Jun Hyung
- Real Birth Name: Yong Jae Soon(Hangul: 용재순) but changed to Yong Jun Hyung (Hangul: 용준형) when he was in the 6th grade
- Date of birth: December 19, 1989 (1989-12-19)
- Position: Main Rapper, Dancer
Jun Hyung also featured in Hyuna's solo debut single "Change". Jun Hyung along with 4minute were also featured in "Heard 'Em All" for Amerie's Asian version of the album In Love & War. He was also a guest rapper for K.Wills song "Present". He also starred in MBC High Kick Through the Roof as a cameo in one of its episodes.  He was also involved in the rap making and featuring for 4minute’s album "Hit Your Heart" where his composing skills were dutifully noted. Jun Hyung was featured for G.NA’s album title song ‘I’ll Back Off So You Can Live Better’ music video, his appearance giving an opposite vibe from Doo Joon's. Currently, Jun Hyung is featured for FADDY ROBOT FOUNDATION together with 4minute`s Hyunah, Outsider, Verbal Jint, Mighty Mouth’s Ssangchu, Vasco and Jico; all profit from this album has been promised to be given out to charity. In order to encourage the public participation in commemorating Seoul Summit Asia Bridge Contents (Representative Choi Jin) had announced that the G20 summit held in Seoul have created campaign song ‘Let’s Go’ composed by Shinsadong Tiger, Lim Sanghyuk, Eddie, and BEAST`s Yong Junhyung. Junhyung will also be rapping for the song. Junhyung will be a guest rapper for chaeyeon song namely 'Ma Lover' on SBS inkigayo on October 31, 2010.
On November 23, 2010, Young Jee released a single named "Crazy, that's what love is" featuring Junhyung in rap making and the rapping. On January 19, 2011, Navi released a single named "Go Again" featuring Junhyung rapping. 
Yang Yo Seob
- Birth name: Yang Yo Seop (Hangul: 양요섭)
- Date of birth: January 5, 1990 (1990-01-05)
- Position: Main Vocalist, Dancer
Along with fellow BEAST member Jun Hyung, MC Lee Hyukjae, Moon Hee Jun (formerly of H.O.T.) and Kim Sook, Yo Seop welcomed Japanese tourists for "Visit Seoul 2010" campaign, where Korean celebrities and Japanese tourists explored Seoul in MBC's Star Guide Doshiraku to raise awareness of Seoul's famous areas as well as its delicious cuisine. On July 16, 2010, Yo Seop participated in the More Charming by the Day official soundtrack in promotion for the film with the song "Happy Birthday". On November 29, 2010 , Yoseop will be releasing a digital single together with Dalmatian`s Daniel, namely "First Snow and First Kiss". Starting from when they were trainees, they were coined 'soulmates0115'. The two had an intimate relationship, prior to their debut, they released a UCC series, "To Pick On Mr. Daniel" which even succeeded to rise up as a hot topic when selected as #1 amongst the weekly TOP 5 UCC's by a sports newspaper. Yoseop is currently a regular cast member on "100 Points Out of 100" which was originally known as "Oh My School" and replaced "Star Golden Bell". YoSeop will be casting his first musical as JiYong through ‘Kwang Hwa Moon Love Song’; The Musical will start performances from March 20th until April 10th.
Lee Gi Kwang
- Birth name: Lee Gi Kwang (Hangul: 이기광), pronounced 'Ki Kwang'
- Date of birth: March 30, 1990 (1990-03-30)
- Position: Lead Vocalist, Main Dancer
Gi Kwang is featured in K.Will's music video for the song, Present. He was also chosen as the model for the ‘Ice Tea Tio’ from DongSuh Foods. Lee Gi Kwang will be featuring in Ahn Jinkyung’s title song ‘Love is Pathetic’ off of her second mini album ‘BE THE VOICE’ this will be his first project that he will be rapping in. Doojoon, Gi Kwang and IU appeared as special hosts on Music Core on August 21, 2010. Gi Kwang will be doing CF filming of LG Tromm cf with model Lee Nayoung. Gi Kwang was casted as the comical role in the drama ‘My Princess’ starring Song Seunghun and Kim Taehee. On December 29, 2010, Gi Kwang was awarded with Popularity Award from the 2010 MBC Entertainment Awards.
Son Dong Woon
- Birth name: Son Dong Woon (Hangul: 손동운)
- Date of birth: June 6, 1991 (1991-06-06)
- Position: Vocalist, Rapper, Dancer, Maknae